This nutrient is not abundant, but it is essential to life. it is part of dna and rna and a component of bones and cell membranes.

Phosphorus

Explanation:

Phosphorus is a vitally important element in the growth and health of plants and animals. As hydroxyapatite, phosphorus is an important constituent of teeth and bones. As adenosine triphosphate (ATP), or other organic phosphates, the element plays an indispensable role in biochemical processes. All biological mechanisms that use phosphorus use it in the form of orthophosphate or, alternatively, as polyphosphate, which, by hydrolysis, becomes orthophosphate. Examples of these processes are photosynthesis, fermentation, metabolism, etc.

In living animals, phosphorus is also a constituent element of nervous tissue as well as cellular protoplasm.

For this reason we can say that phosphorus is not an abundant nutrient but is essential for life. It is part of DNA and RNA and a component of bones and cell membranes.

"it built up in the atmosphere"

i think thats it, idk, i tried looking for this exact q& a for grad. and idk if i got this question right or sorry if im wrong